general help-s2 engine

[jay walker]

after some help and too ppick the brains of the experts really, ive just got a 1991 s2 having had a scirocco for about 3 years. much as i loved my rocco i am in a lil out of my depth in relation to injection engines, turbos and so on (im used to a 1.8 8v carb).

im after some advise on what parts to use, the car has been remapped to about 280 bhp, and im after a it more and a smoother delivery. firstly the turbo is sometimes unpredictable, i found one leak on a vacuum hose so am hoping i can find the other 1(s).

my plans are pretty basic really, put a bigger intercooler, and new dump/BOV, and an exhaust, and a new air intake system

can anyone recomend a dump or BOV (i dont know which does what )that is a direct replacement, (i wont be fitting it due to time restraints, but the more direct the replacement the better.) i dont want anything to shhhhhhhhh'y but would like a subtle noise.

exhaust: ive read that the cats must be retained for MOTs but people have found ways round this, ie. bolt on ones. is it worth increasing the diameter of the exhaust or is standard bore sufficient? also are the exhaust manifolds on ebay any good for the price?!

air intake.....ummm yea, i dont know, heard alot about rs2 ones. but frankly i dont have a clue, is it worth it with a standard turbo?

as i said i am mechanically minded and love working on cars, so any other advice on things to do would be much appreciated, but i dont have much spare time so am restricted. thanks in advance for any help or advice anyone can offer,

jay

[Sonic]

Changing to an RS2 airbox and replacing the stock exhaust system will make a huge difference to the feeling of the car, allowing it to breath freely.

DV - There are quite a few that are direct replacements, i have a forge 007, of which there are some currently in the for-sale section. It provides a nice subtle sound on gear changes and does its job or re-circulating air rather than dumping it with a big WOOOSHHH.

The RS2 airbox is a direct replacement to the stock one with the primary difference that they have a bigger inlet pipe. But they are like hens teeth to buy second hand, and are expensive to buy new. I can assure they make a remarkable difference though!

For a replacement exhaust system you want a minimum of 2.75", or 3" if you dont mind the noise of are going for >350bhp.

A popular setup is the milltek but they have stopped producing the downpipe.

As your car is a 3b i dont think you need the cats, i remember reading a thread recently about it.

HTH

[Rusty]

Along with the obvious, a set of Samco intake hoses, complete replacement of all the vacuum hoses and a proper boost leak test will pay for themselves time and time again. Boost leaks will lose can lose you lots of power.

Other than that it's as Sonic says. Other inlet option is to modify the stock airbox, it's a free mod and works well for me Better to get an ABY airbox on there tho, same with the IC, samll changes and quite cheap too compared to RS2 items.

[GazzaG60]

no cats needed.

the BOV is designed to stop compressor (turbo)n stall. when you are on boost and lift off the throttle closes. the turbo needs somewhere to get rid of the boosted air thats otherweise trapped creating pressure on the turbo. the release of this pressure is done via a bov. i run a GFB atmospheric valve. idont want the hot air back in the intake. best to avoid balies or forge IMO.

read corky-bells maximimum boost. a great book .

[Ross]

Welcome,

Just to confirm - you can put some decat pipes in for a starter as you don't need cats to pass the MOT on a '91. Ideally replace the exhaust from the downpipe back, would go for 2.75" for a bit more performance and if you want to hear the engine a bit more! The downpipe adds a fair bit to the price but definitely worth doing. Unles you want serious power and don't mind the noise, I'd avoid the 3" at your level - will save costs and hassle.

Go with a recirc valve, Forge or equivalent item as Sonic says, don't use a vent-to-atmosphere / BOV as they lose metered air (Some do on here tho without issues).

You'll get a very lively 295bhp out of the stock turbo on a 3B if you do all the right mods, sounds like you have the right ideas but as Andy Casey said check + sort the boost leaks first!!

Cheers
Ross

[jay walker]

massive thanks for the help and the welcome from all! i shall book the car in to have the leaks looked at and get a recirc valve on order. can any recomend a direct replacement that would be ok: thios one?
http://cgi.ebay.co.uk/FORGE-FMCL007P...1%7C240%3A1318
saw a thread about after market intercoolers, anyone know if these still being batch made?

looks like a 2'75 it will be then, ill get a quote on it tomorrow, is it worth changing the manifold?

once again thanks to all.

Jay

[S2central.net]

You need to be careful with aftermarket intercoolers... some of the generic eBay ones can be a PITA to fit... requiring bumper modifications and such. Not impossible - just more work.

You have two easy upgrade choices though on a '91 3B - the RS2 intercooler - or the RS2 Evo intercooler product from Wagner Tuning in Germany - one of our sponsors.

Take your time to read up on technical aspects of the S2 - if you are mechanically apt then you'll pick it up - don't rush into any purchases - weigh up some options first of all. I was a bit bamboozled by turbos and such when I first got my S2 in 2001... Checkout www.s2central.net for some useful background info - its far from complete though ... Read up on the sticky threads in the engine area as well.

Oh and welcome BTW !

[macspring]

Are both parties correct?

GazzaG60 says - "I run a GFB atmospheric valve".

Sonic says - "Go with a recirc valve, Forge or equivalent item as Sonic says, don't use a vent-to-atmosphere / BOV as they lose metered air (Some do on here tho without issues)".

Absolutely no desire to start anything here, but can both parties be right for their own particular applications or to come clean and be thinking about my own car, which scenario is the most suitable for a chipped ABY?

Thanks and kind regards to all.

[S2central.net]

Ahh the old dump valve argument.......

Dump to atmos if you like the wooshy noise on every feckin gear change.
Recirculate if you don't - and feel the marginal benefit of better performance thru the gears... On a recirc it helps keep the compresor spinning, but with a dump valve it is more likely to slow down. We are talking about small benefits here - not like half a second on 0-60 times.

The other option is a hybrid valve which has controls for the amount of dump and recirc effect - like from Turbosmart.

[macspring]

Thanks Paul,

No need for me to think about changing from the S3 one then.

Kind regards.

[newsh]

Welcome new 3B dude

Stock S3 recirc valve (710n ?) is a good upgrade from the 3B item, find yourself an ABY airbox to replace the 3B one and you should also be able to find a second hand Miltek system there've been a few sold on here in the last few months.